Overload release means for a cylinder corn sheller



April 20,1965 M. F. ARMS ETAL 3, 7

OVERLOAD RELEASE MEANS FOR A CYLINDER CORN SHELLER Filed May 18 1962 INVENTOR.

MLO FARMS 8 DONALD E. REED ATTORNEYS Unitd Stats Paten a 3,179,110 OVERLOAD RELEASE MEANS FOR A CYLlNDER CORN dHELLER Milo F. Arms and Donald E. Reed, Cleveland, @hio,

assignors to Bartlett-Snow-Pacific, End, Cleveland,

Ohio, a corporation of California Filed May 18, 1962, er. No. 195,753 2 Claims. (til. 130-6) This invention relates in general to an improved corn sheller of the rotary cylinder type, wherein ear corn is introduced through an inlet or hopper adjacent one end of said sheller and shelled therein, the shelled corn gravitating to the bottom of the sheller for subsequent removal therefrom, and the cobs and husks are removed from said sheller at a point remote from said inlet. More particularly, the invention relates to an improved cylinder construction for shellers of this type.

In prior cylinder shellers, the inadvertent introduction of foreign objects, e.g., rocks, metallic objects or similarly hard foreign materials, into the sheller has been a constant source of damage. The'cylinder of course carries teeth, which serve to agitate and advance the mass, and the clearance between the shelling cylinder and the outer, at least partially perforated, enclosure therefor is not particularly great in the most successful shellers of this type, so that jamming can occur quite readily with potentially severe consequent damage and costly shut-down for repairs.

There have been various attempts to minimize damage on such account, but none have met with marked sucto the inlet of the sheller, functioning in conventional manner to reduce the size of the material fed to the interior of the sheller. Although this use of a crusher ahead of the sheller can prevent some sheller damage, its use is accompanied by marked disadvantages which tend to more than offset the intended advantage thereof. Such a crusher thus almost invariably produces an excessive amount of fine material in the shelled product, and the initial cost of the crusher and the maintenance and operating costs attending the use thereof are considerable. Also, the use of a crusher in this manner generally requires an additional vertical space above the sheller to mount the crusher, which may not always be conveniently available.

It has also been proposed to use a sound detecting device which would function to cut 01f the power to the sheller motor when a predetermined noise level is detected therein, reliance of course being placed on a substantial increase in the noise level within the sheller due to rock, tramp iron or the like in the feed. This expedient, however, is not completely reliable, since excessive damage can still be caused due to the inertia of the sheller cylinder and drive means therefor subsequent to the power shutolf. Also, before the sheller motor can be restarted, it is here required that the sheller be cleaned out to an extent sufficient to enable the motor to start under the residual load.

With the above in mind, it is a primary object of the invention to provide a sheller cylinder assembly wherein positive protection is atforded in the event of predeter miner excessive torque on the drive thereof indicative of jamming or the development of such a condition.

Another object of the invention is to provide such an assembly wherein the cylinder comprises multiple axial sections, the initial one of which, in the feed direction, is automatically disconnected from the drive when a jam occurs, while the remainder continues to be driven, thereby to advance and discharge by the continued operation thereof the mass in the machine beyond such initial section.

3,l7%,l 2. Patented Apr. 20, 1965 Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings: 7

FIG. 1 is a side elevational view of a corn sheller constructed in accordance with the invention, certain por-. tions thereof being broken away to expose normally enclosed structure;

FIG. 2 is an enlarged longitudinal section of the cylinder assembly of the invention, with the usual teeth omitted for convenience; and

FIG. 3 is an enlarged fragmentary view of a portion of the cylinder structure of FIG. 2, showing more clearly the means employed for coupling the initial section of the cylinder to the drive shaft.

Referring now to the drawings, wherein like reference characters are used to designate like parts, the cylinder sheller of the invention is generally indicated at 10 and comprises a floor supported frame generally indicated at 12, said frame including a transverse vertical plate 14 secured to one end thereof and a second vertical plate 16 secured at the opposite end of said sheller frame. A pair of spaced, longitudinally extending structural members 18, only one of which can be seen in FIG. 1, extends longitudinally relative to the sheller frame and the vertically extending plates 14 and 16 are secured thereto. Further longitudinal frame members 20*, one of which is shown in FIG. 1, are spaced on either side of the sheller frame and are positioned vertically above the frame members 18 to provide rigidity, with the frame members 20 being connected at their opposite ends to the plates 14 and 16.

A feed hopper or inlet 22 is provided adjacent one end of the sheller, such hopper being constructed in conventional fashion with an open top and bottom whereby material fed thereto can gravitate therethrough into the interior of the sheller. A semicylindrical hood 24 is securely mounted on the members 20 and forms the top of the sheller, extending from the hopper to the removed end of the frame.

A semicylindrical screen 26 is provided below the hopper or inlet 22, as can be seen in FIG. 1, while a full cylindrical screen (not shown) extends from approximately the rear of the hopper to the remote vertical end plate 16. The perforations of these screens are of such size to pass grain corn, whereby the corn is centrifugally and otherwise expelled to fall into a bottom hopper from which it can be transported by any suitable means.

At the opposite end of said sheller there is a housing 28 here immediately adjacent the plate 16, with this housing enclosing fan or blower means (not shown) capable of disposing of the cobs and husks received from the shelling area. The plate 16 has an aperture therein providing communication from the sheller interior to the fan or blower. Such cobs and husks are blown by said fan means upwardly through pipe 30 for discharge from the sheller to any suitable receiving means. In this assembly, the sheller is further provided with ducts 32 and 34 for inducing air flow across the bottom discharge of i the sheller, for cleaning the shelled corn, and an adjustable air inlet unit is provided for admittance of ambient air to the sheller adjacent the fan.

The above, briefly described, subject matter is known and is disclosed in detail in US. Letters Patent 3,013,565, to which reference may be had for further desired particulars. The foregoing description will be sufiicient to provide a clear understanding of the present improvements.

The rotary shelling cylinder assembly of the invention is generally indicated at 36 and extends from the front portion of the feed hopper longitudinally through the sheller and terminates in the area adjacent the vertical plate 16. This assembly 36 is adapted to be driven by a drive shaft 38 supported at the front end of the sheller by means of a pillow block 40 and at the rear end of the cylinder by a similar pillow block (not shown), with the drive shaft 38 connected in installation of the sheller to a suitable drive motor. As shown in FIG. 1, the periphery of the sheller cylinder assembly is provided with a plurality of teeth 42 which are spaced longitudinally and circumferentially thereon, said teeth when rotated agitating the ears of corn within the screen means for shelling in the usual manner of such a machine. The teeth 42 are preferably arranged helically on the periphery of the cylinder assembly to assist the movement of the material longitudinally toward the opposite end of the sheller and thus to the cob blower.

Referring now particularly to FIGS. 2 and 3, the cylinder assembly 36 illustrated comprises two distinct axial sections 44 and 46. It should be noted that, for purposes of clarity, the pillow blocks which support the drive shaft 38 have been eliminated from FIGS. 2 and 3, as well as the usual teeth. The cylinder section 46 is fixed on the shaft 38 by means of a pair of spaced disc hubs 48 carrying set screws 50 which serve to lock the hubs to the shaft. The cylinder section 46 preferably comprises two arcuate plates held together and on the hubs 48 by clamping bands or rings 52 at the hub occurrences. Suitable bolts 54 or the like fasten such rings to the hubs 48. It will thus be seen that the axial section 46 will rotate at all times with the shaft 38.

The front axial section 44 is adapted to freely rotate on the shaft and is normally coupled therewith by means to be described below. The axial section 44, similarly as the axial section 46, preferably comprises a plurality of two arcuate segments retained on hubs 56 and 58 by means of clamp rings 60, said retainer rings being firmly secured around these segments by having the ends interconnected by bolts 62. The hubs 56 and 58 are freely rotatable on the drive shaft 38. The hub 58 has positioned adjacent one end thereof a safety collar 64 which is spaced from said hub by means of a washer 66, such safety collar being fixed to the shaft 38 and functioning to prevent longitudinal movement of the axial section 44 in the direction of collar 64 when axial section 44 becomes disengaged from shaft 38 under conditions to be described below. There is normally a slight separation of the adjacent ends of the axial sections 44 and 46, as shown.

A cylinder 68 is preferably positioned over inner axial extensions of hubs 56 and 58 and fixed thereto. The cylinder 63 serves to rigidify the axial section 44 by providing an inner connection between the hubs 56 and 58 in addition to the outer connection formed by the arcuate segments referred to above defining the cylindrical wall of the section 44. In addition to rigidifying the axial section 44, the cylinder 68 functions as an additional means of transmitting the torque from the hub 56 to the hub 58, as will be made more apparent hereinbelow. The cylinder 68 serves yet a third function, namely, to prevent abrasives and other material from entering the areas between shaft 38 and hubs 56 and 58. Grease fittings (not shown) are preferably associated with each hub 56 and 58 and provide the usual function of supplying grease to the interiors'thereof to accommodate rela- .tive rotation between the shaft 38 and the axial section 44.

Referring now to the coupling between shaft 33 and the axial section 44, and particularly to FIG. 3, a drive disc '70 is mounted outwardly from the hub 56 on shaft 38 and secured thereto by a key and set screw arrangement. Specifically, the shaft 38 is provided with a key slot 72, such key slot corresponding in width to a similarly shaped key slot provided in the disc 70. The subsequent insertion, when said key slots are aligned, of a key member 74 provides a nonrotatable connection between the disc 70 and the shaft 38. This nonrotatable connection is further strengthened by the application of pressure by means of a set screw '76 which extends through a threaded opening in the disc 70 in conventional manner.

A shear pin generally indicated at 78 is fixed in a radially spaced opening in disc 70 provided therefor by means of a set screw 80. The shear pin 78 comprises a cylindrical end portion 82 which is thus received and locked in the disc 70, an intermediate reduced section 84 and a cylindrical other end portion 86. The hub 56 is provided with an opening 88 of very slightly greater diameter than the outside diameter of the cylindrical portion 86, whereby said cylindrical portion 86 is adapted to fit closely in such opening. Although there is only one such shear pin 78 shown, it will be understood that a plurality of such pins may be provided if desired.

Referring now to the operation of the disclosed sheller, and particularly to the novel cylinder assembly of the invention, ears of corn are fed to the sheller through the hopper 22, such ears being agitated by the teeth 42 of the cylinder assembly 36 and the shelled corn gravitating to the bottom discharge hopper. During periods of normal operation both the axial sections 44 and 46 rotate with the shaft 38, as explained above. The cobs and husks are conveyed to the opposite end of the sheller to be removed therefrom by the fan or blower means in the manner set forth above and further described and illustrated in the U5. Letters Patent referred to above. a foreign object of significant size enters the sheller and becomes wedged between the axial section 44 and the surrounding screen, the drive connection between hub 56 and shaft 38 is immediately broken, i.e., the shear pin 78 is sheared at its reduced area 84. When such shearing occurs, the axial section 44 ceases to rotate, but the axial section 46 continues to rotate. Thus, any materials in the form of husks and cobs which are in the sheller in the area surrounding the cylinder section 46 will continue to be conveyed toward the opposite end of sheller for expulsion therefrom in the above described manner. The sheller is therefore cleared of all material therein with the exception of material about the initial axial section 44.

When a foreign object inadvertently enters the hopper 22 and causes such disconnection between the axial section 44 and the shaft 38, all that is required to again establish the rotatable connection therebetween is to stop the sheller motor and remove the severed shear pin, with clearing of the foreign object and replacement of the pin. The drive coupling of the initial cylinder section 44 is thus disrupted in the event of predetermined excessive torque, established by the strength of the interconnecting pin in such respect.

Referring back to FIG. 1, there are indicated at a and b the approximate longitudinal distances of the axial sections 44 and 46, respectively, of the cylinder assembly 36, with these approximated distances intended to illustrate relative lengths that have been employed with highly satisfactory results. As thus shown, the longitudinal distance of axial section 44 is approximately 30% of the total longitudinal distance covered by a plus b. The initial section, generally speaking, of the sheller cylinder assembly of course experiences relatively heavy loading and, in fact, most of the grain corn is removed in the region of the illustrated section 44. Coupled with this factor is the preferred machine discharge of as much material as practicable in the event of protective disconnect of such section, by the remaining driven section, and

When

the proportions of the two sections may vary although it would be expected that the further section permanently fixed to the shaft would be at least one-half the total length for significant advantage in the noted respect. It will, moreover, be clear that an initial section disconnect will be readily evident by back-up of the feed, and the operator can tell when the still operative section has exhausted the material thereahout by watching the blower discharge.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be emp oyed.

We, therefore, particularly point out and distinctly claim as our invention:

1. A corn sheller of the type described comprising a housing, blower means disposed adjacent one end of said housing for removing cobs and husks from the shelling area, a drive shaft extending longitudinally through said housing, cylinder means positioned around said shaft and adapted to be rotated thereby, said cylinder means comprising a plurality of axial sections at least one of which is rotatable on said shaft and adapted to be driven thereby, the other section being fixed to said shaft and positioned adjacent said blower means, coupling means interposed between said one section and said shaft for rotating said one section, said coupling means including drive disc means fixed to said drive shaft, shear pin means inter connecting said drive disc means and said one axial section whereby rotation of said drive shaft is transmitted to said one axial section through said coupling means, the occurrence of predetermined excessive torque in the coupling means causing shearing of said shear pin means, thereby disabling said coupling means and allowing relative rotation between said one cylinder section and said drive shaft.

2. The combination of claim 1 wherein said one axial section is rotatably mounted on said shaft by means of axially spaced hubs, one of said hubs receiving said shear pin means, and cylinder means secured to and extending between inner axial extensions of said hubs.

References Cited by the Examiner UNITED STATES PATENTS 736,615 8/03 Montgomery 130-6 1,482,516 2/24 Hofmann 130-6 1,558,502 10/25 Power 146-107 1,850,279 3/32 Dieterich 130-6 2,919,075 12/59 Pfeiifer 24132 X 2,927,587 3/60 Arms 130-6 T. GRAHAM CRAVER, Primary Examiner.

J. SPENCER OVERHOLSER, ARNOLD RUEGG,

Examiners. 

1. A CORN SHELLER OF THE TYPE DESCRIBED COMPRISING A HOUSING, BLOWER MEANS DISPOSED ADJACENT ONE END OF SAID HOUSING FOR REMOVING COBS AND HUSKS FROM THE SHELLING AREA, A DRIVE SHAFT EXTENDING LONGITUDINALLY THROUGH SAID HOUSING, CYLINDER MEANS POSITIONED AROUND SAID SHAFT AND ADAPTED TO BE ROTATED THEREBY, SAID CYLINDER MEANS COMPRISING A PLURALITY OF AXIAL SECTIONS AT LEAST ONE OF WHICH IS ROTATABLE ON SAID SHAFT AND ADAPTED TO BE DRIVEN THEREBY, THE OTHER SECTION BEING FIXED TO SAID SHAFT AND POSITIONED ADJACENT SAID BLOWER MEANS, COUPLING MEANS INTERPOSED BETWEEN SAID ONE SECTION AND SAID SHAFT FOR ROTATING SAID ONE SECTION, SAID COUPLING MEANS INCLUDING DRIVE DISC MEANS FIXED TO SAID DRIVE SHAFT, SHEAR PIN MEANS INTERCONNECTING SAID DRIVE DISC MEANS AND SAID ONE AXIAL SECTION WHEREBY ROTATION OF SAID DRIVE SHAFT IS TRANSMITTED TO SAID ONE AXIAL SECTION THROUGH SAID COUPLING MEANS, THE OCCURRENCE OF PREDETERMINED EXCESSIVE TORQUE IN THE COUPLING MEANS CAUSING SHEARING OF SAID SHEAR PINS MEANS, THEREBY DISABLING SAID COUPLING MEANS AND ALLOWING RELATIVE ROTATION BETWEEN SAID ONE CYLINDER SECTION AND SAID DRIVE SHAFT. 